Horn Shedding in Deer

Antlers are the horns of deer. Unlike true horns, antlers are shed every season. Deer are part of the family Cervidae, which includes moose and elk. The only deer that do not have antlers are the small, jungle "vampire" deer, who have long canine teeth instead. All other males of the deer family have antlers. Most female Rangifer tarandus, the caribous and reindeer, also grow and shed antlers.

  1. Growth and Shedding

    • Antlers grow and are shed once a year.

      Deer grow and are shed antlers over the course of the breeding season. The antler bud appears in spring, soon after fawns are born. Female deer nurse their fawns during the summer and become ready to breed in the fall. While females are nursing, males grow antlers to help them compete for mates.

    Velvet

    • New antlers are covered with velvet.

      Velvet is the temporary skin that allows antlers to grow and be shed. Antler velvet is made of skin covered with extreme short and soft hair. It is filled with blood vessels that nourish the growing antler. When the antlers are finished growing, the deer scrape them against trees and rocks to remove the velvet. The antlers only last a short time after the velvet is shed.

    Bone and Pedicle

    • The pedicle grows and sheds the antlers.

      Antlers are made of bone. They grow from a bony protuberance on the deer's skull called a pedicle. At the base of the antlers is a hollow space filled with bone marrow. When the deer is ready to shed, the pedicle cuts off the blood supply to the bone marrow and seals the base of the antler, killing the bone tissue. The antlers detach with a popping noise. This process is completely painless to the deer.

    Defense

    • Deer use their antlers for defense.

      Antlers are used for defense. Sometimes deer use them to defend against predators. Usually they are used to defend mates against other deer. Deer may spar with their antlers, but they rarely engage in serious fights. Most defense is achieved by using the antlers to intimidate the adversary.

    Mate Selection

    • Deer use their antlers for attraction.

      Antlers can intimidate rival males, but they can also impress females. Some evidence shows that females are attracted to the largest males with the healthiest, most impressive antlers.

    Reasons for Shedding

    • Antlers shed because they are too demanding to maintain year-round.

      Since deer only breed during a short period every year, antlers are unnecessary most of the time. They are shed because maintaining them is very risky. Deer must flee from predators often, usually through brush and forests with low-hanging branches. Antlers can become tangled in this growth, leaving the deer at the mercy of predators. Live antlers also demand a great deal of nutrients, including high levels of calcium. These nutrients are not available in adequate quantities during winter and early spring, when food for most species of deer is covered by snow and ice, and when the deer are not breeding.